Exploring the relationship between adolescent physical activity and anthropometric parameters

Purpose: To investigate the contribution of objectively measured light, moderate and vigorous physical activity to body mass index (BMI) and waist circumference-to-height ratio (WCHt) in adolescents. Methods: A total of 694 adolescents (12–18 years) from six secondary schools in Auckland and two in Wellington, New Zealand, participated in the Built Environment and Physical Activity in New Zealand Adolescents study between February 2013 and September 2014. Light, moderate and vigorous intensity physical activity was objectively assessed using ActiGraph GT3X+ accelerometers, which were worn for an 8-day period. Participants’ weight, height and waist circumference were measured to calculate BMI and WCHt. Multiple linear regression was used to characterize independent continuous associations between the percentages of wear time spent in each physical activity intensity with BMI and WCHt. Results: Vigorous activity was inversely independently associated with WCHt (R2 = 0.013, p < 0.01), whereas both light (R2 = 0.053, p < 0.01) and moderate (R2 = 0.036, p < 0.01) physical activity show significant, positive independent relationships with WCHt and BMI. Conclusion: Only vigorous intensity physical activity was associated with key positive health outcomes in adolescents. Our data support the concept of emphasizing the importance of vigorous activity in youth physical activity guidelines. © 2016, Springer-Verlag Italia.